OUTLINE: This is a dose-escalation study. Patients receive flavopiridol IV over 1 hour on day 1. Treatment continues every 3 weeks in the absence of disease progression. A cohort of 3-6 patients receives treatment at each dose level of flavopiridol. If dose-limiting toxicity (DLT) occurs in no more than 1 of 6 patients, subsequent cohorts of 6 patients each receive escalating doses of drug on the same schedule. Intrapatient dose escalation to the next level is permitted in the absence of DLT.